This invention relates to a new family of charged metallophosphate-based molecular sieves designated AlPO-85. They are represented by the empirical formula of:R+rMm2+EPxSiyOz where M is a divalent framework metal such as magnesium or zinc, R is an organoammonium cation, and E is a trivalent framework element such as aluminum or gallium.
Classes of molecular sieves include crystalline aluminophosphate, silicoaluminophosphate, or metalloaluminophosphate compositions which are microporous and which are formed from corner sharing AlO4/2 and PO4/2 tetrahedra. In 1982, Wilson et al. first reported aluminophosphate molecular sieves, the so-called AlPOs, which are microporous materials that have many of the same properties as zeolites, although they do not contain silica (See U.S. Pat. No. 4,310,440). Subsequently, charge was introduced to the neutral aluminophosphate frameworks via the substitution of SiO4/2 tetrahedra for PO4/2+ tetrahedra to produce the SAPO molecular sieves as described by Lok et al. (See U.S. Pat. No. 4,440,871). Another way to introduce framework charge to neutral aluminophosphates is to substitute [Me2+O4/2]2− tetrahedra for AlO4/2− tetrahedra, which yields the MeAPO molecular sieves (see U.S. Pat. No. 4,567,029). It is furthermore possible to introduce framework charge on AlPO-based molecular sieves via the simultaneous introduction of SiO4/2 and [M2+O4/2]2− tetrahedra to the framework, giving MeAPSO molecular sieves (See U.S. Pat. No. 4,973,785).
Numerous molecular sieves, both naturally occurring and synthetically prepared, are used in various industrial processes. Synthetically, these molecular sieves are typically prepared via hydrothermal synthesis employing suitable sources of Si, Al, P, metals, and structure directing agents such as amines or organoammonium cations. The structure directing agents reside in the pores of the molecular sieve and are largely responsible for the particular structure that is ultimately formed. These species may balance the framework charge associated with silicon or other metals such as Zn or Mg in the aluminophosphate compositions, and can also serve as space fillers to stabilize the tetrahedral network framework. Molecular sieves are characterized by having pore openings of uniform dimensions, having a significant ion exchange capacity, and being capable of reversibly desorbing an adsorbed phase which is dispersed throughout the internal voids of the crystal without significantly displacing any atoms which make up the permanent molecular sieve crystal structure. Molecular sieves can be used as catalysts for hydrocarbon conversion reactions, which can take place on outside surfaces as well as on internal surfaces within the pore.
Applicants have synthesized a new family of charged metallophosphate framework materials that contain a +3 valence metal, such as aluminum or gallium, and additionally at least one of a +2 valence metal (such as magnesium or zinc) and silicon, designated AlPO-85. When the +3 valence metal is Al, this corresponds to SAPO, MeAPO, and MeAPSO compositions. The microporous AlPO-85 materials can be prepared with novel morpholinium-based templates as described by Nicholas et al. in U.S. Pat. No. 9,522,896. The AlPO-85 materials have a unique topology that falls in the class of structures known as ABC-6 nets (see AMERICAN MINERALOGIST, 66, 777-788 (1981)).